Valve system timing device



June 2, 1959 J. GRATZMULLER 2,883,953

VALVE SYSTEM TIMING DEVICE Filed Jan. 7, 1957 2 Sheets-Sheet 1 III II Lw s r IL M 7 0 M H H .I I IWH HH HH H H HHH I I I I I m. w n. m 2

@fi Thmii Mm \I w g Q 9 3 FICM United States Patent C VALVE SYSTEMTlMlNG DEVICE llean Louis Gratzmuller, Paris, France Application January7, 15957, Serial No. 632,833

Claims priority, application France January 18, 1956 Claims. (Cl.137-630.15)

This invention relates to a device for timing the operation of a valvesystem.

The main object of the invention is to provide a device of this type,wherein the timing is ensured by a liquid pressure responsive valveactuating piston associated with suitable return means having at leastits active stroke hydraulically controlled by a preferably sharp-edgedcalibrated orifice through which hydraulic liquid flows as the valveactuating piston is displaced.

With this arrangement, the speed of displacement of the valve actuatingpiston is regulated and substantially proportional to the square root ofthe pressure of the said hydraulic liquid.

Another object of the invention is to associate the above-describedliquid pressure responsive valve actuating piston with a valve system soas to actuate successively a number of valves as the valve actuatingpiston travels its active stroke and/or its return stroke.

Still another object of the invention is to provide such atime-controlled valve system with a primary control valve operativelyconnected with the abovementioned liquid pressure responsive valveactuating piston to control its feeding and/or the exhaust of hydraulicliquid therefrom. Under these conditions, the instant of actuation ofsaid primary control valve constitutes the time origin for the timing ofthe valve system. More precisely, the origin of the timing operationsduring the active stroke of the valve actuating piston will correspondto the actuation of the primary valve for feeding the valve actuatingpiston, while the origin of the timing operations during the returnstroke will correspond to the actuation of the primary valve for exhaustof liquid from the valve actuating piston.

Therefore, the present invention has for an object to provide aflow-controlling means interposed in a liquid utilization circuitbetween a source of liquid under pressure and a pressure-liquidreceiving line which includes a chamber of a predetermined volume, afirst conduit means between the source and the chamber and secondconduit means between the source and the line. Calibrated restrictionmeans are interposed in both said first and second conduit means so asto be effective to maintain similar flow characteristics therein, andvalve means are operatively associated with said first and secondconduit means and operable when open to establish two liquid flowsthrough the restriction means. In addition, manually actuated means areprovided to operate the valve means in the first conduit means to openposition, whereupon responsive to fiuid entering the chamber means areeffective to substantially simultaneously operate the valve means in thesecond conduit means to open position. Further valve means are operablyassociated with said second conduit means to be capable of changing theflow conditions between the source and the line, and means are providedoperable responsive to the filling of the chamber to open said furthervalve means to efiect change of flow conditions, whereby a predeterminedvolme of liquid substantially proportional to the volume of PatentedJune 2, 1959 ICC the chamber is supplied to said line before saidfurther valve means opens regardless of variations in the pressure ofthe source.

A more specific object of the invention is. to provide a valve systemincluding a timing device of the type described, wherein at least one ofthe controlled valves is interposed in a hydraulic circuit fed withpressure liquid from the same source as said valve actuating piston,sharp-edged orifices being interposed both in said circuit and in thepipe system of the valve actuating piston and wherein said valveactuating piston is operatively connected with said 1ast-rnentionedvalve in such a manner that the said valve is open during apredetermined fraction of the stroke of said valve actuating piston.

In connection with the timing system or flow-controlling means of theinvention, it is to be expressly pointed out that the pressure in thesource, being constituted by an oleo-pneumatic accumulator, is so highthat the effect of any back pressure load on the liquid-receiving lineis negligible.

With this arrangement, the volume of liquid flowing in said circuit whensaid valve is open is well-defined. This results from the facts that thevolume of liquid flowing to or from the chamber containing said valveactuating piston within the said stroke fraction is welldefined whilesaid volumes are both proportional to the square root of the pressuredrop in said source and hence, in a constant ratio.

p being the pressure in the source,

2" the duration of the valve actuating piston stroke within which thesaid valve is open,

the amount of liquid flowing into or from the said valve actuatingpiston as the same effects the said stroke, due to the presence of thesharp-edged orifice in the pipe system of the valve actuating piston,the said amount of liquid may be expressed as follows:

v0=tK /p K being a constant.

Similarly, U0 being the volume of liquid flowing in the utilizationcircuit within the time 2 during which the valve is open, owing to thepresence of a sharp-edged orifice in the said circuit is:

Uo=tK fgi K being a constant.

The ratio between these two volumes is then:

I being the length of the above-mentioned valve actuating piston strokeand S being the cross-section of the valve actuating piston.

Thus, finally:

which formula exclusively includes fixed or constant values, so that U0has a well-defined value that depends neither on the pressure in thesource nor on the duration of the fraction of the valve actuatingpiston-stroke during which the valve is open.

In other words, this arrangement permits flowing through a utilizationcircuit a predetermined amount of liquid even if the pressure in thesource of said liquid happens to vary. Thus a well-defined and] limitedflow of liquid will be obtained Whenever the primary valve of the systemis actuated. For example, this will permit imparting a stroke ofwell-defined amplitude and regulated speed to a liquid pressureresponsive valve actuating piston by a mere push-button like actuationof a primary valve.

A more specific object of the invention is to provide a valve'system ofthe type described, adapted to ensure feeding of a utilization circuitwith pressure liquid in two successive steps corresponding to differentrates of flow.

A still more specific object of the invention is to provide a valvesystem of the type described in the last paragraph, wherein the firststep of feeding is controlled by a valve associated with a sharp-edgedorifice, as described above, and wherein the feeding of the utilizationcircuit is ensured by the same source as the feeding of the actuatingpiston.

With this arrangement, during the said first step, the utilizationcircuit is fed with a predetermined amount of liquid.

In an embodiment of the invention, the two-step operation of theabove-described valve system is preceded by the closing of a dischargevalve for the liquid pressure responsive valve actuating piston, whichvalve is open when the said actuating piston is not fed with pressureliquid. In this embodiment, the operation of the valve system comprisesthree steps. Step 1: preliminary stroke during which the exhaust valveis closed; step 2: predetermined stroke within which only one valve isopen; step 3: final stroke during which the second valve is opened, thefirst one remaining open or not.

Still another object of the invention is to control a second utilizationcircuit by means of the primary valve of the valve system describedabove, the said second utilization circuit being not, however, under thecontrol of the liquid pressure responsive valve actuating piston. Thispermits disposing of a second control means actuated before the actionscontrolled by the valve system both during the active and the returnstrokes of the actuating piston.

Preferred embodiments of the invention will be hereinafter describedwith reference to the accompanying drawings, given merely by way ofexample.

In these drawings:

Figure l is an axial sectional view of a valve system controlled by aliquid pressure responsive valve actuating piston, according to theinvention, for ensuring two different rates of feeding of a utilizationcircuit.

Figure 2 is a similar view of another embodiment in which the said valvesystem further ensures, prior to said feeding, the interruption of anexhaust circuit.

In both embodiments shown in the drawings, the liquid pressureresponsive valve actuating piston provided for controlling the operationof the valve system comprises a piston 1 slidably mounted in a cylinderformed in a casing 2. The valve system controls the feeding of autilization circuit 3 from a source of hydraulic fluid constituted inthe example shown, by an air-and-oil accumulator 4.

The outlet pipe of the accumulator 4 is shown at 5 and 6 denotes a pipefeeding the utilization circuit 3 under the control of the valve system.

In the examples shown the actuating piston itself is fed from theaccumulator 4 through the above-mentioned outlet pipe 5 and another pipe7, on which are interposed suitable means for controlling the feedingand/or exhaust of the said actuating piston. In both examples shown,said means are constituted by a primary valve 8 comprising a ball 9continuously urged towards its seat by a spring 10. The ball 9 may betaken oil? its seat by means of a manual control knob 11 of which thereturn spring is shown at 12.

An exhaust controlling sliding valve 39 is interposed between the pushknob 11 and the ball 9.

When the knob 11 is depressed the sliding valve 39 first closes anexhaust outlet 42 and then the ball 9 is taken 01f its seat to establisha communication between the already mentioned feeding pipe 7 and alongitudinal passage 13 leading directly to the cylinder or chamberaccommodating piston 1. Conversely, at rest, the ball 9 interrupts thesaid communication while the sliding valve 39 is clear of or uncoversthe outlet 42, so as to establish a communication through an exhaustpipe 40 between the longitudinal passage 13 and a tank 38.

In the examples shown, the actuating piston 1 is continuously urgedtowards its resting position by a spring 14. It carries a rod 15 tightlysliding in a hollow axial boss 16 of the casing 2. The cylindrical bore18 of the boss 16 communicates at its lower end with a counterbore 19 ofgreater diameter, an annular shoulder 20 inter-connecting the innerwalls of said bore and counterbore.

In the counter-bore 19 is slidably mounted a hollow cylindrical valve21, provided with a reinforced end 21', which remains outside thecounter-bore 19 in the cylindrical chamber 22, which has a diametergreater than that of the said counter-bore, and which is connectedtherewith through a frusto-conical shoulder 23 that constitutes the seatof the movable valve 21. The latter is continuously urged towards thesaid seat by a spring 24. The chamber 22 communicates with the abovementioned pipe 6 through an axial passage 25 provided in the head 26 ofthe casing. The valve 21 controls the communication between the saidchamber 22 and a radial outlet 27 that communicates with the utilizationcircuit 3 through the counter-bore 19.

The valve 21 further comprises an axial cylindrical bore 28 opening inits upper face and a counter-bore 29 leading to its other face, i.e. tothe chamber 22; the said counter-bore 29 is connected with the bore 28through an annular shoulder 30 acting as a seat for a ball 31.

The freedom of the motion of the ball 31 in the counter-bore is limitedby a thin partition provided with a central calibrated hole 51preferably constituting a sharp-edged orifice.

The rod 15 of the piston 1 is integral with a needle 32, the lower endof which is adapted to actuate the ball 31. For this purpose, the needle32 is, of course, longer than the bore 28 to a predetermined extent ofwhich the exact value will be defined later.

Finally, in the example shown in Figure 1, a sharpedged orifice 33 isinterposed on the pipe 7, i.e. between the source of hydraulic fluid 4and the primary valve 8.

Under these conditions, the exhaust of liquid from the actuating pistonthrough the outlet 42 is not opposed by the sharp-edged orifice 33 whichonly controls the feeding of the actuating piston.

This device operates as follows:

When the control knob 11 is depressed, it first closes the exhaustoutlet 42 and takes the ball 9 off its seat to establish a communicationbetween the actuating piston and the accumulator 4 under the control ofthe orifice 33. Oil from the accumulator 4, is then sent to theactuating piston with a rate of flow which, as indicated in thepreamble, is substantially proportional to the square root of thepressure in said accumulator.

Immediately after leaving its resting position (or after a neutralstroke corresponding to the clearances existing in the mechanism), thepiston 1 lifts the ball 31 through the rod 15 and the needle 32 toestablish a communication between the accumulator 4 and the utilizationcircuit 3 under the control of the sharp-edged orifice 51 through thepipes 5 and 6, the axial passage 25, the chamber 22, the sharp-edgedorifice 51, the counter-bore 29, the bore 28, the radial port 43, thecounter-bore 19 and the outlet 27. From this moment, the circuit 3 isfed with a rate of flow which is substantially proportional to thesquare root of the pressure in the accumulator 4. Under theseconditions, the amount of oil sent into the utilization circuit within agiven time, is proportional to the amount of oil sent into the chamberaccommodating the actuating piston within the same time. Theseconditions prevail as long as the end 15 of the rod 15 does not comeinto contact with the valve mov; able member 21 as described hereafter.

As a result, during that portion of the stroke of piston 1, which iscomprised between the opening of the valve 21 and the actuation of thevalve 31, a predetermined amount of oil, independent of the pressure, issent into the utilization circuit 3.

As it continues its stroke, the piston 1 after its rod 15 has come intocontact with the valve member 21, lifts the latter off its seat, whichestablishes a second higher rate of feeding including, on the one hand,a direct flow from the accumulator towards the utilization circuit 3through the pipes 5 and 6, the axial inlet 25, the chamber 22, thecounter-bore 19, and the outlet 27, and, on the other hand, a flowthrough the above described circuit passing through the sharp-edgedorifice 51. This is due to the fact that in both examples shown, duringthis second step of the operation of the valve system both valves 31 and21 are simultaneously open.

In the embodiment of Figure 2, the above described valve system ensures,further to the two previously described rates of feeding, the priorclosing of an exhaust valve 44 integral with the needle 32 andcooperating with the seat 45 integral with the rod 15, the said valve 44being open when the actuating piston is not fed to establish acommunication between the utilization circuit 3 and an exhaust pipe 37leading to a tank 38 through the counter-bore 19, a longitudinal passage34 provided along generatrices of the valve 21, an axial bore 35 of thepiston rod 15, a radial port 36 in the Wall of the said rod and the mainbore of the casing 2.

The closing of the valve 44 is ensured at the beginning of the stroke ofthe piston 1 by the seat 45 which is pressed against the said valvewhereupon this pushing connection allows the opening of the valve 31 bythe needle 32 against the action of a spring 55 which ensures both thereturn of the movable assembly hi-32 and the tightness of the exhaustvalve.

This device is completed, in the example shown in Figure 2, by aderivation line 41 provided to feed a second utilization circuit inparallel with the circuit 3 without this second feeding being subjectedto the control of the valve 21. On the other hand, in this example, thesharp-edged orifice 33 is interposed between the root of the line 41 andthe actuating piston. Owing to this arrangement, the feeding and theexhaust of the actuating piston are both controlled by the sharp-edgedorifice 33, while the latter has no action whatsoever on the secondutilization circuit associated with the derivation line 41. The feedingand exhaust of this second circuit are however controlled by the primaryvalve 8.

In a general manner, while it has been, in the above description,disclosed what deemed to be practical and efficient embodiments of theinvention, it should be well understood that it is not wished to belimited thereto as there might be changes made in the arrangement,disposition and form of the parts without departing from the principleof the present invention.

Furthermore it should be pointed out that in this specification as wellas the appended claims, the control of a rate of flow by means of asharp-edged orifice as a function of a pressure in the source does notmean the absolute pressure in the source, but its relative pressure withrespect to that of the system to be fed. This simplification isperfectly justified particularly in the example described since duringthe first time of the operation of the valve system the pressure in theassembly and the pressure in the utilization circuit are bothpractically negligible with respect to the absolute pressure in thesource.

What is claimed is:

l. A flow-controlling means interposed in a liquid utilization circuitbetween a source of liquid under pressure and a pressure-liquidreceiving line, comprising means defining a chamber of a predeterminedvolume, a first conduit means between the source and the chamber and asecond conduit means between the source and the line, calibratedrestriction means interposed in said first and second conduit means andeffective to maintain similar flow characteristics therein, valve meansoperatively associated with said first and second conduit means andoperable when open to establish two liquid flows through saidrestriction means, manually actuated means to operate the valve means insaid first conduit means to open position, means operable responsive toflow of liquid into said chamber to substantially simultaneously operatethe valve means in said second conduit means to open position, furthervalve means operable to change the flow condi tions between said sourceand said line, and means operable responsive to the filling of saidchamber to open said further valve means to effect said change of flowconditions, whereby a predetermined" volume substantially proportionalto the volume of the chamber is supplied to said line before saidfurther valve means opens regardless of variations in the pressure ofthe source.

2 A flow-controlling means interposed in a liquid utilization circuitbetween a source of liquid under pressure and a pressureliquid-receiving line, comprising means defining a chamber of apredetermined volume, first conduit means between said source andchamber, second conduit means between said source and said line,calibrated restriction means interposed in said first and second conduitmeans and effective to maintain similar flow characteristics thereinvalve means between each restriction means and said chamber and linerespectively and operable when open to establish two liquid flowsthrough said restriction means, manually actuated means to operate thevalve means in said first conduit means to open position, means operableresponsive to flow of liquid into said chamber to substantiallysimultaneously operate the valve means in said second conduit means toopen position, further valve means operable to change the flowconditions between said source and said line, and means operableresponsive to the filling of said chamber to open said further valvemeans to efiect said change of flow conditions, whereby a predeterminedvolume substantially proportional to the volume of the chamber is supplied to said line before said further valve means opens regardless ofvariations in the pressure of the source.

3. A flow-controlling means as claimed in claim 1 including a casing,said casing having a cylindrical pistonaccommodating portion therein, apiston within said portion, said chamber being defined by the interiorof said portion and a face of the piston, said first conduit meanscomprising an inlet port means associated with the casing in axiallyspaced relation with respect to said piston, said casing having passagemeans therein having one end in communication with said pistonaccommodating portion and the other end in communication with said inletport means, said passage means further having a surface incorporatedtherewith defining a valve seating, said firstmentioned valve meansincluding a first movable valve operatively associated with said passagemeans between said inlet port and said piston accommodating portion andmeans normally holding said first movable valve on said valve seating,means operably associated with said piston and normally urging the sameaxially of said casing to a position in which the interior of saidpiston accommodating portion of the casing has minimum volume, saidsecond conduit means comprising an outlet port associated with saidcasing in axially spaced relation with respect to said piston, a secondinlet port associated with said casing in axially spaced relation withrespect to said first inlet port and means in the interior of saidcasing defining a further passage providing communication between saidsecond inlet port and said outlet port, a second valve seating in saidfurther passage, both said first and second mentioned inlet ports beingin communication with said source of liquid under pressure, said furthervalve means being movable and operatively associated with saidsecond-mentioned valve seating,

movable valve is open, the means operable responsive to the filling ofsaid chamber including means operably coupled to said piston to engagesaid further valve means to move the same to open position in responseto a predetermined piston movement toward said outlet port when saidfirst movable valve is open and fiuid fiows from source to the pistonaccommodating portion of the casing, the expansion of the volume of saidpiston accommodating portion in response to piston movement sufiicientto open said further valve means defining the predetermined volume ofsaid chamber, the means operable responsive to the flow of liquid intosaid chamber including additional means coupled with said piston forinitiating movement of said second movable valve in response to initialmovement of said piston, the other of said calibrated restriction meansbeing interposed between said source and said piston accommodatingportion of the casing, and said manually actuated means including amovable member for initiating opening movement of said first movablevalve whereby fluid flows from source into said piston accommodatingportion to initiate movement of said piston toward said outlet port, soas to move said second movable valve to open position to substantiallysimultaneously establish communication between source and said outletport whereby said two liquid flows of similar characteristics areestablished following which, in response to further movement of saidpiston, said further valve means is opened to establish ditferent flowconditions from source through said outlet port.

4. A flow-controlling means as claimed in claim 3 in which said manuallyactuated means comprises a push button, spring means normally urging thesame to inoperative position, said movable member being mounted in 5. Aflow-controlling means as claimed in claiml4 and further including asecond outletport for connection to a second line, said second outletport being associated with said casing and with said first-mentionedpassage means downstream of said first movable valve, an exhaust portoperably associated with said casing and said first passage means, saidmovable member of the manually actuated means being adapted to closesaid exhaust port before opening said first movable valve, a secondexhaust port associated with said casing between said piston and saidfirst outlet port, said means in the interior of the casing definingsaid further passage means including a boss within the casing having atubular extension accommodating said further valve means and said secondvalve seating, said further valve means having a diameter less than saidtubular extension so as to define a fluid passage on the interior ofsaid extension, the means extending between said piston and said secondmovable valve including a tubular portion having a port forcommunication with said second exhaust port and a spring biased valvemember accommodated by said further valve means, said spring biasedvalve member being normally open, whereby with both said first andsecond mentioned movable valves closed fluid can flow to exhaust fromsaid first-mentioned line through the tubular extension of said boss,past said last-mentioned movable valve member and out of the casingthrough said second exhaust port whereas in response to actuation ofsaid push button said movable member moves said first movable valve toopen position, fluid enters the piston accommodating portion afterpassing through one of said calibrated restriction means, said pistonmoves toward said first outlet port so as to substantiallysimultaneously close communication with said second exhaust port andmove said second movable valve to open position to permit fluid to flowout of said outlet port through said other calibrated restriction meanswhereupon further piston movement initiates opening movement of saidfurther valve means through which liquid flow continues from sourcethrough said first outlet port.

References Cited in the file of this patent UNITED STATES PATENTS1,592,951 McLaughlin July 20, 1926 2,073,168 Newell Mar. 9, 19372,564,896 Gustafsson Aug. 21, 1951 2,663,500 Holtzclaw Dec. 22, 19532,780,296 Heigis Feb. 5, 1957

